[ImgBot] Optimize images

*Total -- 438.55kb -> 351.42kb (19.87%)

/docs/operator_hub.png -- 90.54kb -> 68.67kb (24.15%)
/docs/bridge_connect_grafana_ocp.png -- 133.03kb -> 101.89kb (23.41%)
/docs/grafana_ui_datasource_view.png -- 61.01kb -> 48.71kb (20.17%)
/docs/grafana-operator-installed.png -- 59.03kb -> 49.62kb (15.94%)
/docs/Example_Add_DataSource.png -- 44.45kb -> 38.19kb (14.08%)
/docs/grafana_ui_login_view.png -- 50.49kb -> 44.34kb (12.19%)

Signed-off-by: ImgBotApp <[email protected]>

Author: ImgBotApp